Dog reunited with owner after 53 days in the desert

[Dowly]

Originally Posted by August

Yeah as I figured it's not as simple as Dowly implies. For example stream water can also suspend Guardia.


http://bwca.cc/tripplanning/waterfiltration.htm

Said page also says what I said (like, right above the bit you quoted ):

And pass on stagnant water, Jordan advises. ''Stagnant water, standing water
with no influent or effluent streams to replenish the source, is certainly a
candidate for chemical treatment. So are waters that are rich in suspended
solids, like algae-rich and silt- or clay-rich waters.''

Of course, if you have the equipment, you can drink from pretty much any source.
But if you suddenly find yourself in a situation where you need to survive, like
the doggie in the OP, I'd suggest using a moving water source as drinking water.